1. Field of the Invention
The present invention relates to a stent that expands a lumen in the body.
2. Description of the Related Art
Methods of recovering a stent indwelled in the body are disclosed in Jpn. Pat. KOKAI Publication No. 10-192411 and U.S. Pat. No. 5,474,563. With these methods, the opposite ends of the stent are pulled in the axially opposite directions thereof, respectively, to contract the stent in its radial direction so that the stent can be recovered from a lumen in the body. Further, EP No. 423916 discloses a method of contracting a trailing end of the stent in its radial direction to pull it out for recovery.
In particular, constriction of a lumen in the pancreatic and bile duct system often occurs as a result of an ulcer. If the stent is indwelled in a lumen in such a site for a long time, mucosa in the lumen may engross through stitches of the stent or the like or the stent may adhere to the mucosa.
Thus, to recover the indwelling stent, it must be released from the mucous membrane. Accordingly, it is conventionally difficult to recover the stent.
Further, if the indwelling stent is of a self expanding type, it is pressed against the mucosa in the lumen. Consequently, it is conventionally difficult to pull the stent out for recovery without damaging the mucosa in the lumen.